(1) Field of the Invention
This invention relates to a pitot tube assembly for actuating a marine speedometer.
Such assemblies normally include a streamlined body or blade member with a pressure-transmitting passage extending through the blade member from a sensing orifice at the lower end with a tube attached to the passage at the upper end of the blade member for transmitting the pressure to the speedometer.
(2) Description of the Prior Art
Pitot tube assemblies of the type to which the subject invention relates also incorporate a bracket for rotatably supporting the blade member so that the blade member will normally be maintained in a downward operative position but may be rotated to a raised position. The bracket is normally mounted on the rear transom of a boat with the blade extending downwardly below the boat. It frequently occurs that the blade will engage an obstacle while moving through the water and therefore must be allowed to rotate upwardly out of the way of the obstacle to prevent damage to the pitot tube assembly. It is also desirable to rotate the blade member of the pitot tube assembly to the raised position when beaching the boat or transporting a boat on a trailer.
Accordingly, there have been pitot tube assemblies developed utilizing separate metal spring assemblies of various structures to urge the blade assembly to the down position but against which the blade may act in rotating to a raised position. Such assemblies have the disadvantage of including numerous parts and the metal components are subject to corrosion and rust.